Cascade filtration / DFPP : Double Filtration PlasmaPheresis
Like TPE, cascade filtration and DFPP allow to remove the larger substances from the blood, such as antibodies, fibrinogen or LDL-cholesterol. Its interest remains in the fact that the plasma is filtered and then returned to the patient, avoiding or minimising the need for replacement fluids. Thus cascade filtration/DFPP applies to both acute and chronic diseases. In case of acute diseases, cascade filtration/DFPP is usually performed as TPE with 5-10 consecutive sessions of 1-2 hours, while for chronic diseases it is performed a few times per year depending on the underlying disease and patient’s situation.
Examples of application
- Auto-immune diseases
- Rejection of transplanted organs
Cascade filtration is a 2 steps process during which plasma is first extracted from the blood and then circulated through a second filter named plasma fractionnator having a pore size approximately 10 folds smaller than a plasmafilter, which retains the larger substances. While in cascade filtration the separation of plasma from blood can be obtained by centrifugation or filtration, in DFPP it is done by filtration only reason why the process can be named double filtration.